[librsvg/attribute-parsers-737: 17/26] ColorMatrix::saturate_matrix() - extract function

[Federico Mena Quintero <federico src gnome org>]

commit 0fea4c7f078d0d516f003c8094bb2fdf577f8d80
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Oct 20 17:13:22 2022 -0500

    ColorMatrix::saturate_matrix() - extract function

 src/filters/color_matrix.rs | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)
---
diff --git a/src/filters/color_matrix.rs b/src/filters/color_matrix.rs
index b31cb9334..763972c8f 100644
--- a/src/filters/color_matrix.rs
+++ b/src/filters/color_matrix.rs
@@ -96,14 +96,7 @@ impl SetAttributes for FeColorMatrix {
                     }
                     OperationType::Saturate => {
                         let s: f64 = attr.parse(value)?;
-
-                        Matrix5::new(
-                            0.213 + 0.787 * s, 0.715 - 0.715 * s, 0.072 - 0.072 * s, 0.0, 0.0,
-                            0.213 - 0.213 * s, 0.715 + 0.285 * s, 0.072 - 0.072 * s, 0.0, 0.0,
-                            0.213 - 0.213 * s, 0.715 - 0.715 * s, 0.072 + 0.928 * s, 0.0, 0.0,
-                            0.0,               0.0,               0.0,               1.0, 0.0,
-                            0.0,               0.0,               0.0,               0.0, 1.0,
-                        )
+                        ColorMatrix::saturate_matrix(s)
                     }
                     OperationType::HueRotate => {
                         let degrees: f64 = attr.parse(value)?;
@@ -225,6 +218,18 @@ impl ColorMatrix {
             0.0,    0.0,    0.0,    0.0, 1.0,
         )
     }
+
+    // https://drafts.fxtf.org/filter-effects/#element-attrdef-fecolormatrix-values
+    #[rustfmt::skip]
+    fn saturate_matrix(s: f64) -> Matrix5<f64> {
+        Matrix5::new(
+            0.213 + 0.787 * s, 0.715 - 0.715 * s, 0.072 - 0.072 * s, 0.0, 0.0,
+            0.213 - 0.213 * s, 0.715 + 0.285 * s, 0.072 - 0.072 * s, 0.0, 0.0,
+            0.213 - 0.213 * s, 0.715 - 0.715 * s, 0.072 + 0.928 * s, 0.0, 0.0,
+            0.0,               0.0,               0.0,               1.0, 0.0,
+            0.0,               0.0,               0.0,               0.0, 1.0,
+        )
+    }
 }
 
 impl FilterEffect for FeColorMatrix {